Nitrilosulphonic Acid, N(SO3H)3

Nitrilosulphonic Acid, N(SO3H)3, has long been known in the form of its potassium salt, which is precipitated in crystalline condition when a mixture of potassium nitrite and potassium sulphite (1 mol.: 3 mols.) is allowed to stand:

KNO2 + 3K2SO3 + 2H2O = N(SO3K)3 + 4KOH.

The nitrilosulphonates can only be prepared by the sulphonation of hydroximidosulphonates, which process resolves itself into treating the corresponding nitrite in this way, since the hydroximidosulphonate has itself to be prepared by a similar sulphonation of the nitrite.